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It sounds to me a bit like the approval or non-approval of the the E15 may be political in some way as much as technical. BMW, Benz, and VW don't approve but Porsche does? How is it that the fuel system components of cars (and bikes) can survive 10% ethanol but will fail at 15%???

It sounds to me a bit like the approval or non-approval of the the E15 may be political in some way as much as technical. BMW, Benz, and VW don't approve but Porsche does? How is it that the fuel system components of cars (and bikes) can survive 10% ethanol but will fail at 15%???

1. Excess heat - ethanol burns hotter than petrol, thus more heat to dissipate
2. not all solvents are created equal. Even gaskets designed to "tolerate" ethanol may survive much longer with e10 than e?? though any gasket chemically formulated to be doused in the cocktail of petrol (aromatics and aliphatics) might not behave well if put into alcohol
3. co-reactions/side reactions of ethanol happen due to the more chemically reactive groups on the ethanol molecule.
4. water will naturally adhere to ethanol from the atmosphere. More ethanol --> more water, less combustion, yadda yadda yadda.

too many variables, especially since e10 is rarely 10% ethanol as it is. If the fudge factor for e10 is +5% /- 1%, imagine how much it gets to be with e15. They aren't allowed to go below the ethanol content, but they can go above.

so for those of us using small(er) gas tanks, older vehicles, etc. the "take-away learning" from this will be "never buy fuel that dispenses from a single hose for multi-grade dispensing".
unfortunately, when in the middle of EBF Idaho... well, we might not have any options.

I try to buy gasoline that is ethanol free if I can. What really would be interesting is what is the reduction in power caused by ethanol is gasoline and how much energy is used to produce ethanol? My suspicion is less power and a large amount of energy used in producing ethanol, so that it may not be as good for the environment as claimed.

I don't want to redirect this thread, but am curious about the above issues. Another thread or references that would clarify this issue would be appreciated.

This can be somewhat confusing. Ethanol doesn't actually burn hotter, but it can cause an engine to run hot. If you don't have a closed loop fuel metering system (like EFI with an O2 sensor) The engine will run leaner than intended with an Ethanol blend fuel. The higher the ethanol percentage, the leaner it runs and the leaner it runs, the hotter it runs.

This can be somewhat confusing. Ethanol doesn't actually burn hotter, but it can cause an engine to run hot. If you don't have a closed loop fuel metering system (like EFI with an O2 sensor) The engine will run leaner than intended with an Ethanol blend fuel. The higher the ethanol percentage, the leaner it runs and the leaner it runs, the hotter it runs.

I finally clicked on the link for "pure-gas" then BC, the province I live in. I guess I can believe that ALL Shell 91 octane contains no ethanol in my home province. If true, that is good to know as my bike supposedly prefers "premium."

I guess I can also believe that ALL Chevron 94 octane contains no ethanol in BC. (NO other stations offer 94 octane in BC.)

What I found unbelieveable was that the 100 Mile House Chevron (this is a very small town well away from population centers) ALONE offers ethanol-free gas in 87, 89, and 92 octane! They send a truck (or is that FOUR trucks, one for each octane?) to service the discerning folk in this small town?

This can be somewhat confusing. Ethanol doesn't actually burn hotter, but it can cause an engine to run hot. If you don't have a closed loop fuel metering system (like EFI with an O2 sensor) The engine will run leaner than intended with an Ethanol blend fuel. The higher the ethanol percentage, the leaner it runs and the leaner it runs, the hotter it runs.

My bike runs lean. I wonder if the fuel I am burning is a large percentage of the cause.

Are you talking about the 1995 K75 you have listed? If so, does the L-Jetronic run closed loop with an O2 sensor or is it open loop, running a pre-programmed map and supplying fuel based on the air volume and proably some other sensors? If it running open loop, it is possible, but it should only have a small impact between gasoline and E10 so it is questionable as to whether or not you would notice it. It depends on how lean BMW designed it to run in the first place. If you are running a higher percentage of alcohol, all bets are off. Other factors such as ignition timing and fuel pressure can play a significant role as well. If the K75 is tempermental on E10, it should be heavily discussed in the K forum.

Even gaskets designed to "tolerate" ethanol may survive much longer with e10 than e?? though any gasket chemically formulated to be doused in the cocktail of petrol (aromatics and aliphatics) might not behave well if put into alcohol
.

That's exactly one of my points. The fuel systems are already designed to tolerate alcohol in the mix. How likely is it the designers of those systems specified for an absolute max at 10%. O rings, gaskets, seals, plastic parts, etc. that will survive 10% will fail at 15%? Not likely IMO.

Originally Posted by arthurdent

water will naturally adhere to ethanol from the atmosphere. More ethanol --> more water, less combustion, yadda yadda yadda.

too many variables, especially since e10 is rarely 10% ethanol as it is. If the fudge factor for e10 is +5% /- 1%, imagine how much it gets to be with e15. They aren't allowed to go below the ethanol content, but they can go above.

Here you're talking about variables and contaminants and they can never be accounted for. Modern fuel systems are isolated from the atmosphere so water take up by the ethanol should not be significant.

I'm no chemical or elastomer expert, but the higher concentration of ethanol starts to degrade certain synthetic rubber materials, harden certain plastics, create nasty acids in the fuel systems. All around a loosing proposition forced on us by the government and lobbyists. E10 and E15 wouldn't be viable on the market if it weren't for the subsidies that offset the higher cost of the product. Subsidies by the way, funded by the taxes we pay.

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An e.g. of a recent repair for me(not on a bike but still were are talking ethanol fuel) is my Kohler sawmill engine. I started it up & have a new fuel leak behind the plastic fuel tank. The engine was built some where around 1998-9. Upon removal the leak is at the output end adjacent to the fuel line nipple exit of the plastic fuel pump. I remove the top of the mechanical pump & glue the crack there after a thorough cleaning & using a product called "Seal All"(yellow tube & smells & looks like thick version of model airplane glue) which is said to be "gasoline" proof I let it cure for 2 days & it has gone through several gallons of fuel OK.
The question for me (as relates to this thread & in talking various components contact with 10% or 15% fuels) becomes , are the terms gasoline dated when we read the label on Seal All type products or in making the decision to buy a plastic replacement part such as the fuel pump? FWIW, some of those engines have plastic or metal mechanical pumps, some have metal electric & some have pulse operated plastic,etc.. I.e., plastic fuel connectors on BMW bikes,etc..?